Donor Acceptor Interactions in the Best Lewis Structure

The localized orbitals in your best Lewis structure
can interact strongly. A filled bonding or lone pair orbital can
act as a donor and an empty or filled bonding, antibonding, or
lone pair orbital can act as an acceptor. These
interactions can strengthen and weaken bonds. For example, a
lone pair donor->antibonding acceptor orbital interaction
will weaken the bond
associated with the antibonding orbital. Conversly, an interaction
with a bonding pair as the acceptor will strengthen the bond.
Strong electron delocalization in your best Lewis structure will
also show up as donor-acceptor interactions.
Interactions greater than 20 kJ/mol for bonding and lone pair
orbitals are listed below.

The interaction of antibonding donor orbital, 3, for S2-O3 with
the bonding acceptor orbital, 79, for S2-O3 is 26.9 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O1 with
the antibonding acceptor orbital, 3, for S2-O3 is 65.6 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O1 with
the bonding acceptor orbital, 79, for S2-O3 is 1870 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for S2 with
the antibonding acceptor orbital, 78, for O1-O3 is 38.7 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O3 with
the antibonding acceptor orbital, 77, for O1-S2 is 49.5 kJ/mol.